Temperature compensated actuator unit with piezo element

摘要

The actuator unit has a sleeve-shaped housing (2) contg. the piezo element (1), whereby upper and lower end sections of the housing have shape and/or force locking connections to the piezo element and to a control device respectively. The housing has at least an inner (331), middle (332) and outer (333) sleeve. The inner sleeve has a force and/or shape locking connection to the piezo element and to the lower section of the middle sleeve. The outer sleeve has a shape and/or force locking connection to the upper end of the middle sleeve and to the control device. The sleeves are made of at least two different materials selected so that the resulting thermal coefficient of expansion of the compound sleeve (33) corresp. to that of the piezo element.